diff --git a/PROGRESS.md b/PROGRESS.md
index f28aa94..79622c6 100644
--- a/PROGRESS.md
+++ b/PROGRESS.md
@@ -17,9 +17,10 @@
 - Admin credentials page with guided Stripe setup flow
 - Encrypted settings for API keys and secrets
 - Search modal with keyboard shortcut
+- Transactional emails (order confirmation, shipping notification)
 - Demo content polished and ready for production
 
-**Next up:** Transactional emails — order confirmation and shipping notifications (Tier 1, Roadmap #3)
+**Next up:** Default content pages — terms, privacy, delivery policy (Tier 1, Roadmap #4)
 
 ## Roadmap
 
@@ -27,7 +28,7 @@
 
 1. ~~**Order management admin**~~ — ✅ Complete (02cdc81). Admin UI at `/admin/orders` with status filter tabs, streamed order table, and detail view showing items, totals, and shipping address.
 2. ~~**Orders & fulfilment**~~ — ✅ Complete. Submit paid orders to Printify, track fulfilment status (submitted → processing → shipped → delivered), webhook-driven status updates with polling fallback, admin UI with submit/refresh actions.
-3. **Transactional emails** — Order confirmation email on payment. Shipping notification with tracking link. Use Swoosh (already configured) with a simple HTML template.
+3. ~~**Transactional emails**~~ — ✅ Complete. Plain text order confirmation (on payment via Stripe webhook) and shipping notification (on dispatch via Printify webhook + polling fallback). OrderNotifier module, 10 tests.
 4. **Default content pages** — Static pages for terms of service, delivery & refunds policy, and privacy policy. Needed for legal compliance before taking real orders. Can be simple markdown-rendered pages initially, upgraded to editable via page editor later.
 
 ### Tier 2 — Production readiness (can deploy and run reliably)
@@ -172,7 +173,7 @@ See: [ROADMAP.md](ROADMAP.md) for design notes
   - CSSCache test startup crash fixed (handle_continue pattern)
 
 ### Orders & Fulfilment
-**Status:** Complete (checkout, admin, fulfilment). Transactional emails pending (Roadmap #3).
+**Status:** Complete
 
 - [x] Orders context with schemas (ff1bc48)
 - [x] Stripe Checkout integration with webhook handling
@@ -191,7 +192,12 @@ See: [ROADMAP.md](ROADMAP.md) for design notes
   - Stripe webhook auto-enqueues submission after payment confirmed
   - Admin UI: fulfilment badge column, fulfilment card with tracking, submit/refresh buttons
   - Mox provider mocking for test isolation, 33 new tests (555 total)
-- [ ] Transactional emails (Roadmap #3)
+- [x] Transactional emails (Roadmap #3)
+  - OrderNotifier module with plain text emails via Swoosh
+  - Order confirmation sent from Stripe webhook after payment + address/email updates
+  - Shipping notification sent from Printify shipment webhook + polling fallback
+  - Guards for missing customer_email, graceful tracking info handling
+  - 10 tests (565 total)
 
 See: [docs/plans/products-context.md](docs/plans/products-context.md) for schema design
 
@@ -208,6 +214,7 @@ See: [docs/plans/page-builder.md](docs/plans/page-builder.md) for design
 
 | Feature | Commit | Notes |
 |---------|--------|-------|
+| Transactional emails | — | Plain text order confirmation + shipping notification, 10 tests |
 | Printify order submission & fulfilment | — | Submit, track, webhooks, polling, admin UI, 33 tests |
 | Order management admin | 02cdc81 | List/detail views, status filters, 15 tests |
 | Encrypted settings & Stripe setup | eede9bb | Guided setup flow, encrypted secrets, admin credentials page |
diff --git a/lib/simpleshop_theme/orders.ex b/lib/simpleshop_theme/orders.ex
index 9af9278..1375f60 100644
--- a/lib/simpleshop_theme/orders.ex
+++ b/lib/simpleshop_theme/orders.ex
@@ -9,7 +9,7 @@ defmodule SimpleshopTheme.Orders do
 
   import Ecto.Query
   alias SimpleshopTheme.Repo
-  alias SimpleshopTheme.Orders.{Order, OrderItem}
+  alias SimpleshopTheme.Orders.{Order, OrderItem, OrderNotifier}
   alias SimpleshopTheme.Products
   alias SimpleshopTheme.Providers.Provider
 
@@ -233,7 +233,13 @@ defmodule SimpleshopTheme.Orders do
         }
         |> maybe_set_timestamp(order)
 
-      update_fulfilment(order, attrs)
+      with {:ok, updated_order} <- update_fulfilment(order, attrs) do
+        if attrs[:fulfilment_status] == "shipped" and order.fulfilment_status != "shipped" do
+          OrderNotifier.deliver_shipping_notification(updated_order)
+        end
+
+        {:ok, updated_order}
+      end
     end
   end
 
diff --git a/lib/simpleshop_theme/orders/order_notifier.ex b/lib/simpleshop_theme/orders/order_notifier.ex
new file mode 100644
index 0000000..171004d
--- /dev/null
+++ b/lib/simpleshop_theme/orders/order_notifier.ex
@@ -0,0 +1,130 @@
+defmodule SimpleshopTheme.Orders.OrderNotifier do
+  @moduledoc """
+  Sends transactional emails for orders.
+
+  Order confirmation after payment, shipping notification when dispatched.
+  """
+
+  import Swoosh.Email
+
+  alias SimpleshopTheme.Cart
+  alias SimpleshopTheme.Mailer
+
+  require Logger
+
+  @doc """
+  Sends an order confirmation email after successful payment.
+
+  Skips silently if the order has no customer email.
+  """
+  def deliver_order_confirmation(%{customer_email: nil}), do: {:ok, :no_email}
+  def deliver_order_confirmation(%{customer_email: ""}), do: {:ok, :no_email}
+
+  def deliver_order_confirmation(order) do
+    subject = "Order confirmed - #{order.order_number}"
+
+    body = """
+    ==============================
+
+    Thanks for your order!
+
+    Order: #{order.order_number}
+
+    #{format_items(order.items)}
+    Total: #{Cart.format_price(order.total)}
+
+    #{format_shipping_address(order.shipping_address)}
+    We'll send you another email when your order ships.
+
+    ==============================
+    """
+
+    deliver(order.customer_email, subject, body)
+  end
+
+  @doc """
+  Sends a shipping notification with tracking info.
+
+  Skips silently if the order has no customer email.
+  """
+  def deliver_shipping_notification(%{customer_email: nil}), do: {:ok, :no_email}
+  def deliver_shipping_notification(%{customer_email: ""}), do: {:ok, :no_email}
+
+  def deliver_shipping_notification(order) do
+    subject = "Your order has shipped - #{order.order_number}"
+
+    body = """
+    ==============================
+
+    Good news! Your order #{order.order_number} is on its way.
+
+    #{format_tracking(order)}
+    Thanks for shopping with us.
+
+    ==============================
+    """
+
+    deliver(order.customer_email, subject, body)
+  end
+
+  # --- Private ---
+
+  defp deliver(recipient, subject, body) do
+    email =
+      new()
+      |> to(recipient)
+      |> from({"SimpleshopTheme", "contact@example.com"})
+      |> subject(subject)
+      |> text_body(body)
+
+    case Mailer.deliver(email) do
+      {:ok, _metadata} = result ->
+        result
+
+      {:error, reason} = error ->
+        Logger.warning("Failed to send email to #{recipient}: #{inspect(reason)}")
+        error
+    end
+  end
+
+  defp format_items(items) when is_list(items) do
+    items
+    |> Enum.map_join("\n", fn item ->
+      price = Cart.format_price(item.unit_price * item.quantity)
+      "  #{item.quantity}x #{item.product_name} (#{item.variant_title}) - #{price}"
+    end)
+  end
+
+  defp format_items(_), do: ""
+
+  defp format_shipping_address(address) when is_map(address) and map_size(address) > 0 do
+    lines =
+      [
+        address["name"],
+        address["line1"],
+        address["line2"],
+        [address["city"], address["postal_code"]] |> Enum.reject(&is_nil/1) |> Enum.join(" "),
+        address["state"],
+        address["country"]
+      ]
+      |> Enum.reject(&(is_nil(&1) or &1 == ""))
+      |> Enum.map_join("\n", &"  #{&1}")
+
+    "Shipping to:\n#{lines}\n\n"
+  end
+
+  defp format_shipping_address(_), do: ""
+
+  defp format_tracking(order) do
+    cond do
+      order.tracking_url not in [nil, ""] and order.tracking_number not in [nil, ""] ->
+        "Tracking: #{order.tracking_number}\n#{order.tracking_url}\n\n"
+
+      order.tracking_number not in [nil, ""] ->
+        "Tracking: #{order.tracking_number}\n\n"
+
+      true ->
+        "Tracking details will follow once the carrier updates.\n\n"
+    end
+  end
+end
diff --git a/lib/simpleshop_theme/webhooks.ex b/lib/simpleshop_theme/webhooks.ex
index d3ba4b0..6c9c0a5 100644
--- a/lib/simpleshop_theme/webhooks.ex
+++ b/lib/simpleshop_theme/webhooks.ex
@@ -4,6 +4,7 @@ defmodule SimpleshopTheme.Webhooks do
   """
 
   alias SimpleshopTheme.Orders
+  alias SimpleshopTheme.Orders.OrderNotifier
   alias SimpleshopTheme.Products
   alias SimpleshopTheme.Sync.ProductSyncWorker
   alias SimpleshopTheme.Webhooks.ProductDeleteWorker
@@ -44,14 +45,17 @@ defmodule SimpleshopTheme.Webhooks do
   def handle_printify_event("order:shipment:created", resource) do
     shipment = extract_shipment(resource)
 
-    with {:ok, order} <- find_order_from_resource(resource) do
-      Orders.update_fulfilment(order, %{
-        fulfilment_status: "shipped",
-        provider_status: "shipped",
-        tracking_number: shipment.tracking_number,
-        tracking_url: shipment.tracking_url,
-        shipped_at: DateTime.utc_now() |> DateTime.truncate(:second)
-      })
+    with {:ok, order} <- find_order_from_resource(resource),
+         {:ok, updated_order} <-
+           Orders.update_fulfilment(order, %{
+             fulfilment_status: "shipped",
+             provider_status: "shipped",
+             tracking_number: shipment.tracking_number,
+             tracking_url: shipment.tracking_url,
+             shipped_at: DateTime.utc_now() |> DateTime.truncate(:second)
+           }) do
+      OrderNotifier.deliver_shipping_notification(updated_order)
+      {:ok, updated_order}
     end
   end
 
diff --git a/lib/simpleshop_theme_web/controllers/stripe_webhook_controller.ex b/lib/simpleshop_theme_web/controllers/stripe_webhook_controller.ex
index d510365..af241e9 100644
--- a/lib/simpleshop_theme_web/controllers/stripe_webhook_controller.ex
+++ b/lib/simpleshop_theme_web/controllers/stripe_webhook_controller.ex
@@ -2,7 +2,7 @@ defmodule SimpleshopThemeWeb.StripeWebhookController do
   use SimpleshopThemeWeb, :controller
 
   alias SimpleshopTheme.Orders
-  alias SimpleshopTheme.Orders.OrderSubmissionWorker
+  alias SimpleshopTheme.Orders.{OrderNotifier, OrderSubmissionWorker}
 
   require Logger
 
@@ -56,6 +56,9 @@ defmodule SimpleshopThemeWeb.StripeWebhookController do
             order
           end
 
+        # Reload items for the email (update_order doesn't preload)
+        order = Orders.get_order(order.id)
+
         # Broadcast to success page via PubSub
         Phoenix.PubSub.broadcast(
           SimpleshopTheme.PubSub,
@@ -63,6 +66,8 @@ defmodule SimpleshopThemeWeb.StripeWebhookController do
           {:order_paid, order}
         )
 
+        OrderNotifier.deliver_order_confirmation(order)
+
         # Submit to fulfilment provider
         if order.shipping_address && order.shipping_address != %{} do
           OrderSubmissionWorker.enqueue(order.id)
diff --git a/test/simpleshop_theme/orders/order_notifier_test.exs b/test/simpleshop_theme/orders/order_notifier_test.exs
new file mode 100644
index 0000000..a3f3a66
--- /dev/null
+++ b/test/simpleshop_theme/orders/order_notifier_test.exs
@@ -0,0 +1,161 @@
+defmodule SimpleshopTheme.Orders.OrderNotifierTest do
+  use SimpleshopTheme.DataCase, async: true
+
+  import Swoosh.TestAssertions
+  import SimpleshopTheme.OrdersFixtures
+
+  alias SimpleshopTheme.Orders
+  alias SimpleshopTheme.Orders.OrderNotifier
+
+  describe "deliver_order_confirmation/1" do
+    test "sends confirmation with order details" do
+      order =
+        order_fixture(%{
+          customer_email: "buyer@example.com",
+          payment_status: "paid",
+          shipping_address: %{
+            "name" => "Jane Doe",
+            "line1" => "42 Test Street",
+            "city" => "London",
+            "postal_code" => "SW1A 1AA",
+            "country" => "GB"
+          }
+        })
+
+      assert {:ok, _email} = OrderNotifier.deliver_order_confirmation(order)
+
+      assert_email_sent(fn email ->
+        assert email.to == [{"", "buyer@example.com"}]
+        assert email.subject =~ "Order confirmed"
+        assert email.subject =~ order.order_number
+        assert email.text_body =~ order.order_number
+        assert email.text_body =~ "Test product"
+        assert email.text_body =~ "Jane Doe"
+        assert email.text_body =~ "42 Test Street"
+        assert email.text_body =~ "London"
+      end)
+    end
+
+    test "includes item quantities and prices" do
+      order =
+        order_fixture(%{
+          customer_email: "buyer@example.com",
+          payment_status: "paid",
+          quantity: 2,
+          unit_price: 1500
+        })
+
+      assert {:ok, _email} = OrderNotifier.deliver_order_confirmation(order)
+
+      assert_email_sent(fn email ->
+        assert email.text_body =~ "2x Test product"
+      end)
+    end
+
+    test "includes order total" do
+      order =
+        order_fixture(%{
+          customer_email: "buyer@example.com",
+          payment_status: "paid",
+          unit_price: 2500
+        })
+
+      assert {:ok, _email} = OrderNotifier.deliver_order_confirmation(order)
+
+      assert_email_sent(fn email ->
+        assert email.text_body =~ "Total:"
+      end)
+    end
+
+    test "skips when customer_email is nil" do
+      order = order_fixture(%{customer_email: nil})
+
+      # Override to nil since fixture sets a default
+      {:ok, order} = Orders.update_order(order, %{customer_email: nil})
+
+      assert {:ok, :no_email} = OrderNotifier.deliver_order_confirmation(order)
+      assert_no_email_sent()
+    end
+
+    test "skips when customer_email is empty string" do
+      order = order_fixture()
+      {:ok, order} = Orders.update_order(order, %{customer_email: ""})
+
+      assert {:ok, :no_email} = OrderNotifier.deliver_order_confirmation(order)
+      assert_no_email_sent()
+    end
+
+    test "handles missing shipping address" do
+      order = order_fixture(%{customer_email: "buyer@example.com", payment_status: "paid"})
+
+      assert {:ok, _email} = OrderNotifier.deliver_order_confirmation(order)
+      assert_email_sent(subject: "Order confirmed - #{order.order_number}")
+    end
+  end
+
+  describe "deliver_shipping_notification/1" do
+    test "sends notification with tracking info" do
+      {order, _v, _p, _c} = submitted_order_fixture(%{customer_email: "buyer@example.com"})
+
+      {:ok, order} =
+        Orders.update_fulfilment(order, %{
+          fulfilment_status: "shipped",
+          tracking_number: "1Z999AA1",
+          tracking_url: "https://ups.com/track/1Z999AA1",
+          shipped_at: DateTime.utc_now() |> DateTime.truncate(:second)
+        })
+
+      assert {:ok, _email} = OrderNotifier.deliver_shipping_notification(order)
+
+      assert_email_sent(fn email ->
+        assert email.to == [{"", "buyer@example.com"}]
+        assert email.subject =~ "Your order has shipped"
+        assert email.subject =~ order.order_number
+        assert email.text_body =~ "1Z999AA1"
+        assert email.text_body =~ "https://ups.com/track/1Z999AA1"
+      end)
+    end
+
+    test "handles missing tracking info gracefully" do
+      {order, _v, _p, _c} = submitted_order_fixture(%{customer_email: "buyer@example.com"})
+
+      {:ok, order} =
+        Orders.update_fulfilment(order, %{
+          fulfilment_status: "shipped",
+          shipped_at: DateTime.utc_now() |> DateTime.truncate(:second)
+        })
+
+      assert {:ok, _email} = OrderNotifier.deliver_shipping_notification(order)
+
+      assert_email_sent(fn email ->
+        assert email.text_body =~ "Tracking details will follow"
+      end)
+    end
+
+    test "includes tracking number without URL" do
+      {order, _v, _p, _c} = submitted_order_fixture(%{customer_email: "buyer@example.com"})
+
+      {:ok, order} =
+        Orders.update_fulfilment(order, %{
+          fulfilment_status: "shipped",
+          tracking_number: "RM123456789GB",
+          shipped_at: DateTime.utc_now() |> DateTime.truncate(:second)
+        })
+
+      assert {:ok, _email} = OrderNotifier.deliver_shipping_notification(order)
+
+      assert_email_sent(fn email ->
+        assert email.text_body =~ "RM123456789GB"
+        assert not (email.text_body =~ "Tracking details will follow")
+      end)
+    end
+
+    test "skips when customer_email is nil" do
+      {order, _v, _p, _c} = submitted_order_fixture()
+      {:ok, order} = Orders.update_order(order, %{customer_email: nil})
+
+      assert {:ok, :no_email} = OrderNotifier.deliver_shipping_notification(order)
+      assert_no_email_sent()
+    end
+  end
+end